If a metering device is too permissive, what is the likely result on head pressure?

When a metering device is described as "too permissive," it allows too much refrigerant to flow into the evaporator coil. This excessive flow can lead to a situation where the evaporator coil does not have enough time to adequately absorb heat from the surrounding air. As a result, not all of the refrigerant is vaporized in the evaporator, leading to an increased pressure in the system.

As refrigerant enters the compressor in a less than optimal state, it can create higher head pressures. The compressor has to work harder to compress the additional liquid or partially vaporized refrigerant, resulting in increased head pressure. Therefore, this condition can lead to efficiency losses and potential system damage if not addressed.

This understanding highlights why the head pressure would likely increase when the metering device is too permissive, aligning with the answer provided.